'Teenage Terminator' ready to battle the best

It is a nickname that might take hold given the way Ariarne Titmus attacks her racing in the manner of a Terminator.

The teenage sensation announced herself as the brightest young star of Australian swimming when she carved a whopping five seconds off her personal best to claim the 400m freestyle women's crown in 4.04.82 at this week's national titles at the Chandler Aquatic Centre.

She also took down reigning distance champion Jess Ashwood in the 800m.

The 16-year-old from Hobart, who is now based in Brisbane, is on a collision course with US sensation Katie Ledecky at the world championships in Budapest in July.

"With Katie being only three years older than me it can be a little intimidating," he said.

"But also it is very exciting that I get to go and race the greatest female swimmer the world has ever seen, so I am really excited."

According to Swimming Australia head coach Jacco Verhaeren, Titmus is fearless.

"Brilliant, an amazing swim," he said of her victory in the 400m.

"That is somebody with an exciting future, definitely."

Titmus's career took off when the family packed up and moved to Queensland 18 months ago so she could join forces with St Peters Western coach Dean Boxall.

His poolside antics were a highlight of the national titles this week as he cajoled his swimmers on to greater efforts.

Titmus says he and recalls a time when he "got up me" for having an ice coffee during the short-course championships in December.

"If he's on my back all the time then that makes me get better; it means I can never relax, I know he's going to keep pushing me," she said.

American swimmer Katie Ledecky.

"He's a bit of a supercoach."

Titmus is the product of the impact Ledecky, the five-time Olympic Gold medallist and holder of world records over 400m, 800m and 1500m, has had on world swimming - a new generation of swimmer that is smashing the previously held assumptions of distance racing.

She bursts out of the blocks, with no regard for self-preservation, daring the pack to catch her while challenging herself to hang on.

While internationally Ledecky is the benchmark, Titmus first had to learn to ignore Australia's reigning distance champion Jess Ashwood, who was dethroned here this week, and do her own thing.

"Dean has taught me not to be scared," she said.

"I used to kind of be a bit afraid if I went out to hard, oh know I've gone too fast and I'm in front of Jess Ashwood.

"But now it's kind of like, I am I this race too and I can do my own thing and go out hard.

"It sets me up in the longer distances, I race better if I am in front and the other girls have to try to catch me."